Chapter XIV.
On the differences in simple fruits and the diversity of leaves, especially on the grapevine and fig leaves, and the various shapes of other leaves.
58. But, in order to simplify the matter, there are some fruits that are cooked by the sun, while others are filled with pulp or enclosed in a husk or rind. Apples and pears, as well as all types of grapes, are exposed to the sun without any covering. However, walnuts and chestnuts, even their kernels, are nourished and nurtured by the heat of the sun, even though they are covered by a shell or husk. And the denser the shell of a pine nut, the more it is nourished by the heat of the sun.
Then how great is the providence of the Lord, that where the fruit is softer, there the thickness of the leaves provides a stronger covering for the fruit, as we see in the fruit of the fig tree. Therefore, the more delicate things must be protected by stronger ones, as the Lord himself teaches through Jeremiah, saying: 'Just as I will recognize these good figs that I have sent from this place to the land of the Chaldeans as good, and I will set my eyes upon them for good.' (Jeremiah 24:5). As if with a certain stronger covering of his mercy, he protected them like delicate ones, lest the ripe fruits perish prematurely. In the end, he says of them even in the following: My delicate ones have walked in rough ways (Baruch, IV, 26). To them he says further below: Be steadfast, O children, and cry out to God (ibid., 27). For this alone is an inviolable covering, an impenetrable fortress against all storms and injuries. Where there are therefore tender fruits, there will be thicker coverings and protections of leaves. On the other hand, where the fruits are stronger, there will be more delicate leaves, as the apple tree shows. For a stronger fruit does not need much help in protection; for the shade itself of a thicker protection could harm the fruit more.
Finally, let the vine leaf teach us the grace of nature, and the internal mysteries of divine wisdom. For we see it so divided and separated, as to seem to show the appearance of three separate leaves: with the middle part distinct, so that it would appear separate to onlookers unless it clung to the lower parts. And this seems to be a design of nature, that it both more easily admits the sun, and covers with shade. Finally, the middle part extends higher, and thins at its very top, so that it presents more beauty than covering. For the grape seems to portray the appearance of a mark, signifying that it has the primacy among the other hanging fruits, to which with a certain silent judgment of nature, but with clear evidence, the mark and prerogative of victory is born. Therefore, it carries its own mark with it, by which it is also provided with protection against the injuries of the air, as well as the violence of rain, and it does not hinder the reception of the heat of the sun, by which it is warmed, colored, and increased. The leaf of the fig tree is also divided into four parts, just like the vine leaf: which is clearer the larger the leaf is, although not as much as the vine leaf or the edge of the leaf, or the top of the curled leaf. Just as the thickness of the fig leaf is stronger, so is the appearance of the vine leaf more elegant. Therefore, the thickness of the leaf helps to repel the damage caused by the weather, while the division helps to release the vapor for the sake of the fruits. Finally, this type of fruit does not quickly perceive hail, but it quickly feels ripeness; because it seems to be able to hide from harm, and to be open to favor.
61. Why should I describe the various differences of leaves, how some are round, some are longer, some are flexible, some are stiffer, some are not easily blown by any winds, some are shaken by a gentle breeze?